Three-letter words:BRR intj. used to indicate coldnessCWM circular basin with steep wallsHMM intj. expressing thoughtNTH pert. to item number nPHT intj. used as an expression of mild anger or annoyanceSHH intj. used to urge silenceTSK to utter a scolding exclamation

If you don't consider y's vowels, there are many possibilities (Think of the puzzle in the 7th guest where you had to make a sentence out of letters where you were given no vowels).
Shy gypsy, shyly, spryly tryst by my crypt.
also, syzygy.
and many others, I'm sure.